We have sold very succesfully an 8 amphr battery that has been used by many
owners of Jabiru and 912 powered aircraft, for starting purposes. The
battery weighs a miserly 2.8 kgs compared to my existing battery which was
already light at 4.8 kgs. The itty bitty battery costs five pounds ($8) more
than its big brother but its the cheapest 4.4 lbs of weight saving on the
plane. Just imagine if you could reduce the weight of a Europa by 100 lbs
for only 180 dollars. I think everyone would go for it.
8 amphr batteries can work but I only sell them where weight is
critical. Cranking current is better than on some 25 amphr batteries but if
the engine doesn't start quick its not going to start at all. They're also
not very good in the testing stage when people have their electics on
without running the engine. If the electrical charging system fails then
there is only 8 amhr of backup.
erry
lts@avnet.co.uk
http://www.avnet.co.uk/touchdown
----- Original Message -----
From: Robert L. Nuckolls, III <nuckolls@aeroelectric.com>
Subject: RE: Battery size
> > Bob,
> > The problem has been discussed about the 12 AMP battery not being
strong
> >enough to "start" the 582 (in all cases). From your answer, it sounds
like
> >you are saying, "The 12 AMP is not sufficient". "The 14 AMP is the next
> >size up so, get that one". Correct??????????????
>
> This is a problem with pat answers based on past
> experience and/or ol' mechanic's tales. I can
> show you a 1.2 a.h. battery that will crank an
> engine perfectly well . . . . several times!
> Bottom line is that EACH battery needs to be
> evaluated on its own merits.
>
> Given the rapid advance of the science in battery
> technologies, I'd hesitate to discount ANY
> idea until it's tried. A fairly general answer
> to using low a.h. batteries to crank engines is
> related to terminal sizes . . . many RG batteries
> have sufficiently low internal impedance to crank
> and engine . . . ya just can't hood a 4 or 6AWG
> wire to them.
>
> B&C has an itty bitty 10 a.h. that he cranked
> a cold IO-360 through a 5 blade starting sequence
> 7-8 times in a row before the battery faded. It's
> terminals are about equal to a 10-30 screw. With
> some care in termination and bolt torque attention,
> this guy could work just fine in a 912 powered
> airplane.
>
> Bob . . .
>
> http://www.aeroelectric.com
>
>
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